On Sat, Jan 09, 2021 at 05:18:34PM -0500, Willem de Bruijn wrote:
> From: Willem de Bruijn <will...@google.com>
>
> esp(6)_output_head uses skb_page_frag_refill to allocate a buffer for
> the esp trailer.
>
> It accesses the page with kmap_atomic to handle highmem. But
> skb_page_frag_refill can return compound pages, of which
> kmap_atomic only maps the first underlying page.
>
> skb_page_frag_refill does not return highmem, because flag
> __GFP_HIGHMEM is not set. ESP uses it in the same manner as TCP.
> That also does not call kmap_atomic, but directly uses page_address,
> in skb_copy_to_page_nocache. Do the same for ESP.
>
> This issue has become easier to trigger with recent kmap local
> debugging feature CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP.
>
> Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
> Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
> Signed-off-by: Willem de Bruijn <will...@google.com>
> Cc: Steffen Klassert <steffen.klass...@secunet.com>
As this patchset goes through the net tree:
Acked-by: Steffen Klassert <steffen.klass...@secunet.com>
Thanks!
